Suppress output from non-PowerShell commands?

powershell output

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Solution 1

Out-Null works just fine with non-PowerShell commands. However, it doesn't suppress output on STDERR, only on STDOUT. If you want to suppress output on STDERR as well you have to redirect that file descriptor to STDOUT before piping the output into Out-Null:

hg st 2>&1 | Out-Null

2> redirects all output from STDERR (file descriptor #2). &1 merges the redirected output with the output from STDOUT (file descriptor #1). The combined output is then printed to STDOUT from where the pipe can feed it into STDIN of the next command in the pipline (in this case Out-Null). See Get-Help about_Redirection for further information.

Solution 2

A fun thing you can do is to pipe the output to Write-Verbose, then you can still see it if you need it by running your script with the -Verbose switch.

ping -n 2 $APP 2>&1 | Write-Verbose

Solution 3

Can also do this

hg st *> $null

Powershell suppress console output

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Author by

Abhishek

I have been a senior developer with a focus on architecture, simplicity, and building effective teams for over ten years. As a director at Surge consulting I was involved in many operational duties and decisions and - in addition to software development duties - designed and implemented an interview processes and was involved in community building that saw it grow from 20 to about 350 developers and through an acquisition. I was then CTO setting up a dev shop at working closely with graduates of a coding bootcamp on both project work and helping them establish careers in the industry. Currently a Director of Engineering at findhelp.org your search engine for finding social services. I speak at conferences, have mentored dozens of software devs, have written popular articles, and been interviewed for a variety of podcasts and publications. I suppose that makes me an industry leader. I'm particularly interesting in companies that allow remote work and can check one or more of the following boxes: Product companies that help people in a non-trite manner (eg I'm not super interested in the next greatest way to get food delivered) Product companies that make developer or productivity tooling Funded startups that need a technical co-founder Functional programming (especially Clojure or Elixir) Companies trying to do something interesting with WebAssembly

Updated on May 26, 2020

Comments

Abhishek about 4 years
I am running a command
```
hg st
```
and then checking it's $LASTEXITCODE to check for availability of mercurial in the current directory. I do not care about its output and do not want to show it to my users.

How do I suppress ALL output, success or error?

Since mercurial isn't a PowerShell commandlet hg st | Out-Null does not work.
Abhishek about 11 years

Awesome. That works. Can you explain what the 2>&1 syntax actually means?
Abhishek about 10 years

This won't suppress STDERR for example if hg is not installed
Bill_Stewart about 10 years

2>&1 means "redirect standard error to the same place as standard output."
Ansgar Wiechers about 10 years

@Bill_Stewart I believe that's what I said, only that I addressed both parts of the operator separately, because other streams could be merged with STDOUT (the success output stream, actually) as well.
Bill_Stewart about 10 years

@AnsgarWiechers - sure. I didn't notice that you had amended your answer after George Mauer asked for clarification.
Ansgar Wiechers over 9 years

@GeorgeMauer Neither does my suggestion. Errors thrown by the host environment are not redirected.
Ansgar Wiechers over 9 years

Note that the *> redirection operator is not available prior to PowerShell v3.